Deflection minimizing double shell heat exchanging rolls



April 23? 1963 A. v. ALEXEFF 3,086,279

April 23, 1963 A. V. ALEXEFF DEFLECTION MINIMIZING DOUBLE SHELL HEAT EXCHANGING ROLLS Filed March 15, 1961 3 Sheets-Sheet 2 INVENTOR Alexa/nder TZZfyef ATTORNEYS April 23, 1963 A. v. ALEXEFF 3,086,279

DEFLECTION MINIMIZING DOUBLE SHELL HEAT EXCHANGING ROLLS Filed March l5, 1961 I5 Sheets-Sheet 5 lNvENToR Alexander VAI/exef BY gf/m ATTORNEYS nit This invention relates to rolls which are used in treating or making web or sheet. material such as calendar rolls, printing rolls, and the like. The invention has applicability to heat-exchanging rolls of the type which circulate cooling or heating fluid for treating metal sheet and slabs and sheet glass and the like, but is not in all its aspects restricted to heat-exchanging rolls.

The invention pertains more particularly to rolls of a deflection minimizing type comprising an outer tubular member supported at points intermediate its center and ends by inner deiiecting structure. Pertinent examples from the prior art involving broadly the same deflectionminimizing type of roll are found in Love Patent No. 886,998 and McArn Patent 2,676,387.

The rolls of the general type to which the invention Irelates involve the concept of minimizing the longitudinal deflection under load of the outer surface of the roll by the manner of support by the inner roll structure. Spaced zones of support are provided so that the total longitudinal deflection of the outer member across the longitudinal extent of an applied load, such as a coacting pressure roll or tensioned webor plastic stock, will be only a very small fraction of the longitudinal deflection of the inner structure across the `same longitudinal extent. Both the outer roll Istructure and the inner structure will experience relatively gross displacement in a transverse direction as the load is applied, but once such relatively gross displacement occurs, the relative uniformity of deiiection along the longitudinal extent of the outer tubular member will allow rolling operations to occur under fload with 4an almost infinitesimal degree of distortion. For example in the case of steel rolls embodying the invention and having a one-foot radius and approximately tiveand-one-half-foot operative (webengaging) length, it is possible under applied loads of 200,000 pounds to maintain uniformity of deflection along the roll surface within tolerances of less than 2O millionths of an inch except at the very ends of the rolls where the tolerance may be slightly over one ten-thousandths of an inch.

A serious problem in the provision of rolls of the deflection-minimizing type has been that of aggravated and excessive wear at the spaced zones of support for the outer roll member as when metal spacer rings or blocks are employed. When the roll is under deliection, the inner Iroll structure is ydistorted with respect to the outer roll structure so that, is the roll turns, there is a relative motion between points on the outer and inner roll members which, under no deflection, rotate together in the same planes of rotation. Y

Such relative motion may be avoided by deforming the inner roll structure so that the relative motion occurs under no load but so that, under load, the inner roll structure is, so to speak, straightened out and both the inner and outer roll structures rotate in the same planes of rotation. However, the straightened out condition of the inner roll member is maintained only at a single `value of `applied load so that the structure must be redesigned or re-adjusted each time a different value of applied value of applied load is encountered.

When it is attempted to employ roller bearings and the like to accommodate the relative motion referred to above over a range of values of applied load, it is found that service life is very brief because of the prohibitively high Bdii Patented Apr. 23, 1963 fic unit-area loadings or pressures at the points of bearing contact. Rubber spacers or the like are quickly destroyed under high loads.

An object of the present invention is to provide a deflection-(minimizing roll which avoids the above defects and which maintains minimal surface deflection without excessive wear of the roll parts while accommodating the relative motions mentioned above, the roll being operable without excessive wear throughout a range of values of the applied load which is limited only by a top value representing the ultimate loading `for which the over-all roll structure is designed. The invention contemplates that the annularly extending spacer means provided for the outer and inner roll structure comprise spacer members, the inner and outer ends of which move relative to each other with a Wobbling motionto cause elastic deflection of the member, with the spacer members being divided from their neighbors in the annular succession of which they are a part, and with each member wobbling and elastically deccting independently of direct restraint by adjacent members.

The invention contemplates` that the spacer members engage bearing faces associated with, and oriented with respect to, the outer and inner roll structure in the manner to be described more particularly below. In one aspect, the invention contemplates that the bearing portions of the spacer members are interrelated to the bearing faces in a manner which limits applied loads at the top and bottom ends of the spacer members to the kerns of the `cross-sections of the spacer members to thereby maintain stresses in the spacer members below the elastic limit of the spacer material under the widest range of variation in initial orientations and operational orientations of the spacer means with respect to the inner and outer roll structure.

The features and advantages of the invention will be more apparent from the Ifollowing description of la specific example thereof.

In the drawings:

FIGURE l is an elevation, partly in section, of a roll embodying the invention.

FIGURE 2 i-s a fragmentary enlarged sectional view of the upper left hand portion of the structure shown in FIGURE l.

FIGURE 3 is a fragmentary cross-section taken on the plane of line 3 3 in FIGURE 2.

FIGURE 4 is a fragmentary cross-section, partly broken away, taken on the plane of line 4-4 in FIG- URE 2.

FIGURES 5, 6, and 7 are views, respectively, of a spacer plate, an outer bearing pad element, and inner bearing pad elements employed in the illustrated example of the invention.

FIGURE 8 is a fragmentary cross-section, partly broken away, taken on the plane of line V8i i in FIGURE l.

FIGURE 9 is a diagrammatic view illustrating certain features of the invention.

As shown in the drawings, there is provided a roll cornprising lan inner cylindrical beam 10 and an outer tubular cylindrical beam l1 which together form a double wall roll structure with a hollow zone l2 between the rolls. Preferably, and in the particular structure illustrated, the central portions of the inner cylindrical beam 116i are enlarged as at 13.

Provided between the inner and outer roll structure l() and 11 are a pair of 4spacer means generally indicated Vby .the reference numerals 21 and 22. The spacer means 2l and 22 are located within the enlarged portion of the hollow zone i2 adjacent the enlarged central portion 13 of the inner cylindrical beam. The -spacer means 21 and 22 are reach in load-bearing relationship with and between the inner and outer roll members 10 and 11. The

emanare spacer means 21 Iand 22 are each located intermediate the longitudinal center of the roll and yan end of the outer tubular beam lll.

FIGURES l-S shofw the undeilected or no-load condition of the roll structure. This rio-load condition is also illustrated in the phantom portion of the FIGURE 9 diagram, in which certain transverse dimensions are grossly exaggerated for purposes of exposition.

The loaded condition is illustrated in FIGURE 9 in solid lines. For the purpose of eliminating extraneous complications in the diagrammatic showing of FIGURE 9, the enlarged portion 13 of the inner cylindrical beam I is not indicated in FIGURE 9.

Each of the spacer means 21 and 22 comprise an annular succession of spacer members, one `of which is shown in FIGURE 2 and tive of which are seen in FIGURE 4. Each of the spacer members has a radially outer end 26 and a radially inner end 27 (see FIGURE 4). In the undeilected or no-load condition `of the roll shown in FIG- URES l-S, both the radially outer ends and radially inner ends 26 and 27 of the spacer members 2l and 22 travel in paths of rotation which lie in the same plane of rotation. In the case of the spacer members 21, this would be the plane 31 indicated in FIGURE 9. For spacer members 22, this ywould be the plane 41 indicated in FIG- URE 9.

In the deflected or load condition of [the roll, the radially inner ends 27 of the spacer members travel in inner paths of rotation which are each in a plane of rotation (planes 32 and 42 in the respective cases of the spacer members 2l and 22) which is skewed with respect to the plane of rotation ofthe outer ends 26 or 27 of the spacer members. The path of rotation of the outer ends of the spacer members remains in substantially the same plane of rotation as in the undeflected condition of the roll. Thus, as may be `seen in FIGURE 9, the paths of rotation of the outer ends 26 of the spacer members 2l and 22 remain in the planes of rotation 31 and 41 even in the solid line deected condition shown.

During rotation `of lthe roll under load, the plane of rotation 31 intersects the inner roll structure along a zone 55, the width of which is substantially twice the distance from the plane 32 to the plane 31 at the periphery of the inner roll structure. In other words, this zone 35 is bounded by the planes 36 and 37 which will be seen to intersect the plane 31 respectively at the top side and bottom side of the inner cylindrical beam as it is illustrated in FIGURE 9.

During rotation of ,the roll under load, the plane of rotation 32 intersects the outer roll structure along a zone 38, the width of which is substantially twice the distance from the plane 31 to the plane 32 at the periphery or spacer-engaging diameter of the outer roll structure. In other words, this zone 38 is bounded by the planes 39 and 40 which will be seen to intersect the plane 32 respectively at the bottom side and top side of the inner periphery of the outer tubular beam 11 as it is illustrated in FIGURE 9.

Similar zones are established in connection with the planes of rotation 41 and 42.

These zones are illustrated in FIGURE 9 for the purpose of exemplifying the range of sliding movement which must necessarily occur in the case of rigid spacing members between the inner and outer roll structure. If the rigid spacing members are rigidly affixed to the inner roll structure, there must necessarily be a relative sliding movement between the spacer members and the outer roll structure equal to the width of the zone 38. This would typically amount to a sliding movement of `approximately .001 in the device of a two-foot diameter steel roll of fve-and-one-half-foot eifective length under a load of 200,000 pounds.

If the spacer members are rigidly aixed to the outer roll structure 11, there must necessarily be a sliding movement between the spacer members and the inner roll structure I0 which in the diagrammatic showing would be of an extent equal to the width of the zone 35. The zone 35 would be slightly narrower ythan the zone 3S but would still comprise a substantial distance of sliding movement which would be highly destructive in its effect.

The invention contemplates the provision of spacer members iwhich independently wobble and clastically deiiect independently of each other in the annular succession of spacer members making up the spacer means 21 or 2.2. The wobbling action is indicated in FIGURE 9 as to the spacer members 22 by the approximate arcs or curves iof deflection thereof between the inner and outer planes of rotation 41 and 42. It will be evident that the delicotion at the top of the roll structure is in the opposite direction or sense from that at the bottom portion thereof, FIGURE 9 being taken in a plane parallel to the direction of application of load so that the deilections of the spacer members 22 represent maximum deflections in each direction.

The spacer members making up the spacer means 2l and 22 each comprise at least one plate 51 (FIGURE 5) and preferably a plurality of such plates as seen most clearly in FIGURE 2.

In one aspect of the invention, the top and bottom edges of the plates 51 are crowned, the radius of the curvature of the crowning exceeding the outside radius of the roll structure. For example in a two-foot diameter roll structure, the radius of curvature a for the top and bottom edges of the plate 51 can be approximately 30 inches.

As seen most clearly in FIGURES 2 and 4-6, there are provided annular arrays of outer bearing pads associated with the outer tubular beam 111 and inner bearing pads associated with the inner beam 10. The outer bearing pads in the particular embodiment illustrated comprise bearing pad elements 55 which are associated with the outer tubular circular beam 11 through a peripherally endless retainer ring or band 56 (FIGURES 2 and 4) which is used to hold the bearing pad elements 55 and the remainder of the spacer means structure in assembled condition during the assembly shrink-fitting together of the inner roll structure 10 and the outer roll structure 1I. The bearing pad elements 55 have bearing faces 58 which face radially inwardly and which remain substantially parallel to the axis of the outer tubular beam both in no-load and in loaded condition of the roll structure.

The inner bearing pads in the particular embodiment illustrated comprise a ring-like element shown in FIG- URE 7 and machined to provide the bearing pad element portions indicated by the reference numeral 65, such bearing pad portions alternating with upstanding spacer portions 66 around the annular extent of the roll. The bearing pad portions 65 have bearing faces 68 which face in the radially outward direction. The structure of FIGURE 7 is doweled at various points around its annular extent to the inner cylindrical beam 10 as shown at 61 in FIGURE 4. The ring 56 is initially held in assembled position before shrink-fitting of the roll structure by bolts 62 received in tapped holes in the upstanding spacer portion 66 as shown in FIGURE 4.

The structure shown in FIGURE 7 lits tightly on the inner cylindrical beam 10. The tight t and the doweled connections assure that the bearing faces 63 will, under load conditions where there is deflection of the inner cylindrical beam, remain parallel to a line which is tangent to the central axis of the inner beam at the intersection of a perpendicular dropped from the bearing face to the central axis of the inner beam. Thus in the diagram of FIGURE 9, a bearing face at the location 71 would in the illustrated deflected condition of the beam be parallel to the tangent line 72 taken at the point of intersection '73 of the central axis 74 of the inner tubular beam with the perpendicular 75 dropped from the bearing face in question. p

The above described array of bearing pads and spacer plates having crowned top and bottom edges results in a linear type contact of the bearing plates with the faces of the bearing pad elements or portions, with the contact lines extending transversely of the roll length.

The slight crowning assures that the applied loads at the top and bottom ends of the spacer members, when the roll is operating under load, will be substantially limited to the kern of the cross-sectionsA of the plates 51.

The spacer elements each comprising a plate or plates 51 are preferably mounted as restrained beams at their lower ends by means of a large spacer and retainer ring 81 provided toward either end of the roll structure in surrounding relationship with the inner cylindrical beam 10. These rings are shrink-iitted on the inner cylindrical beam in snug engagement against the sides of the endmost plate 51 of each spacer element.

To assure that there will be no gross displacement of the annular spacer means assemblies at either end of the roll during emplacement of the outer beam 11 over the inner beam -10 during fabrication of the roll, they are preferably provided with a plurality of bumper pads 83 bolted as shown in FIGURES 2 and 3 to the ring 81 and the enlarged portion 13 of the inner cylindrical beam 10. These members are spaced a very slight distance from the sides of the outer bearing pad elements 55 and are notched to accommodate the sides of the assembly ring 56 as shown in FIGURE 2.

An end ring 91 is provided at each end of the roll for closing off the hollow zone 12. This is of course necessary when heating or cooling fluids are to` be circulated through the hollow zone 12.V

A key 92 may be attached to the ring 91 as shown in n FIGURES 2 and 8. The key coacts with an enlarged slot 93 `formed in the inner cylindrical beam 10. A slight radial clearance at the free end of the key is provided because the deflection of the outer and inner roll structure will differ at this location along the length of the roll structure. Preferably lateral spaces 94 (FIG- URE 8) between the key 92 and the sides of the keyway 93 are provided which are of a considerable width such as to accommodate leaf springs or S springs (not shown) which may be inserted in the longitudinal direction from the end of the roll so as to allow a springloaded lost motion between the rotation of the inner and outer roll structure. The keyway arrangement is provided in order to be sure that there is adequate torque transmitting capacity between the inner and 'outer roll structure independent of the spacer means, although in many instances the spacer means themselves will have an adequate torque transmitting capacity. The springloaded lost motion is provided to allow for slight variances in relative angular velocities of the inner and louter roll structure at the roll ends during each rotation of the roll.

Four such keyways are provided at each end of the roll, at 90 angular intervals.

When heating or cooling fluid is to be circulated through the rolls, drilled passages 96 are provided as shown in FIGURE l, such passages 96 extending up through the inner cylindrical beam 10 from the inner bore 97 at either end of the roll structure and also extending through the sleeve members 8'1. The sleeve members 81 act as llers within the enlarged end portions of the hollow zone 12 so that the velocity of cooling or heating fluid is approximately constant along the length of the roll to promote uniformity of heating distribution. The heating or cooling fluid passes the spacer means 21 and 22 through the spaces 98 as shown in FIGURE 4. A plug 88 within the bore 97 prevents bypassing of the iiuid.

-of rotation of the roll structure. Load-bearing support involves a degree of angular proximity between the parts of each spacer means sufficient to avoid washboarding, that is, sufficient to avoid at all points around the annular extent of Ithe roll any significant structural weakening or Alack of support `between the inner and outer roll structure and the spacer means.

As used herein, and particularly in the following claims, the term slenderness ratio refers to the ratio of radial length to minimum transverse dimension of the one or more elements or plates making up the spacer members of the respective spacer means such as the spacer means 21 and 22. As seen in FIGURE 2, such ratio is in excess of three in the case of the plates 51 in the illustrated example of the invention.

This application is a continuation-impart of my application Serial No. 828,507, tiled July 2l, 1959, now abandoned. f

The invention is not restricted to the slavish imitation of each and every one of the details described above which have been set forth merely by way of example with the intent of most clearly setting forth the teaching of the invention. Obviously devices may be provided which change, eliminate, or add certain specic structural details without departing from the invention.

What is claimed is:

1. A roll comprising an inner cylindrical beam and an outer tubular cylindrical beam forming a double-wall roll with a hollow zone between the walls, annularly extending iirst and second spacer means in said hollow zone and in load-bearing relationship with and between said inner and outer cylindrical beams, said rst spacer means Vbeing located intermediate the longitudinal center of said roll and a tir-st end of lsaid outer tubular beam, said second spacer means being located intermediate the` longitudinal center of said roll vand the opposite second end of said outer tubular beam, each of said spacer means having a radially outer periphery and a radially inner periphery, the radially outer peripheries of said rst and second spacer means traveling respectively in first and second outer paths of rotation, the radially inner peripheries traveling respectively in rst and .second inner paths of rotation, each of said inner paths of rotation being in a plane of rotation which is skewed with respect to the plane of rotation of the associated outer path of rotation when said roll is rotating in laterally deflected condition as when under load whereby during each turn the radially inner and outer peripheries of each spacer means move relative to each other with a wobblinlg motion, each of said spacer means comprising spacer elements each having a -slenderness ratio substantially in excess of unity.

2. A roll comprising an inner cylindrical beam and an outer tubular cylindrical beam forming a double-wall roll with a hollow zone between the walls, annularly extending first and second spacer means in said hollow zone and in load-bearing relationship with and between said inner and outer cylindrical beams, said first spacer means being located inter-mediate the longitudinal center of said roll and a iirst end of said outer tubular beam, said second spacer means being located intermediate the longitudinal center of said roll and the opposite second end of said outer tubular beam7 each of said vspacer means having a radially outer periphery and a radially inner periphery, the radially outer peripheries of said rst and second spacer means traveling respectively in first and second outer paths of rotation, the radially inner peripheries traveling respectively in rst and second inner paths of rotation, each of said inner paths of rotation being in a apenas/e plane of rotation which is skewed with respect to the plane of rotation yof the associated outer path of rotation when said roll is lrotating in laterally deliected condiltion as when under load whereby during each turn the radially inner and outer peripheries of each spacer means move relative to each other with a wobbling motion, each of said spacer means comprising spacer elements divided from each other along contact interfaces which are transverse to the roll length and each spacer element having a slenderness ratio 4substantially in excess of unity.

3. A -roll compiising an inner cylindrical beam and an outer tubular cylindrical beam forming a double-wall roll with a hollow zone between the walls, annularly extending first and second spacer means in said hollow zone and in load-bearing relationship with and between said inner and outer cylindrical beams, said first spacer means being located intermediate the longitudinal center of said roll and a first end of said outer tubular beam, said second spacer means being located intermediate the longitudinal center of said roll and the opposite second end of said outer tubular beam, each of said spacer means having a radially outer periphery and a radially inner periphery, the radially outer peripheries of said first and second spacer means traveling respectively in -iirst and second outer paths of rotation, the radially inner peripheries traveling respectively in rst and second inner paths of rotation, each of said inner paths of rotation being in a plane of rotation which is skewed with respect to the plane of rotation of the associated outer path of rotation when said roll is rotating in laterally deflected condition as when under load whereby during each turn the radially inner vand outer peripheries of each spacer vmeans move relative to each other with a wobbling motion, each of said spacer means comprising at least one annular plate array having its Shortest annular cross-sectional dimension extending in the longitudinal direction of said roll.

4. A roll comprising an inner cylindrical beam and an outer tubular cylindrical beam forming a double-wall roll with a hollow zone between the walls, annularly extending rst and second spacer means in said hollow zone and in load-bearing relationship with and between said inner and outer cylindrical beams, said first spacer means being located intermediate the longitudinal center of said roll and a first end of said outer tubular beam, Isaid second spacer means Ibeing located intermediate the longitudinal center of said roll and the opposite second end of said outer tubular beam, each of said spacer means having a radially outer periphery and a radially inner periphery, the radially outer peripheries of said first and 5 being in a plane of rotation which is skewed with respect to Ithe plane of rotation of the associated outer path of rotation when said roll is rotating in laterally deilected condition as when under load whereby during each turn the radially inner and outer peripheries of each spacer means move relative to each other with a wobblng motion, each of said spacer means comprising at least two annular plate arrays each having its shortest dimension extending in the longitudinal direction of said roll and each divided from the other along a contact interface which is transverse to the roll length and is radially wider than said shortest dimension.

5. A roll comprising an inner cylindrical beam and an outer tubular cylindrical beam forming a double-wall roll with a hollow zone between the walls, annularly extending `first and second spacer means in said hollow zone and in load-bearing relationship with and between said inner and outer cylindrical beams, said first spacer means being located intermediate the longitudinal center of said roll and a first end of said outer tubular beam, Said second spacer means being located intermediate the longitudinal center of said roll and the opposite second end of said outer tubular beam, each of said spacer means having a radially outer periphery and a radially inner periphery, the radially outer peripheries of said first and second spacer means traveling respectively in first and second outer paths of rotation, the radially inner peripheries traveling respectively in first and second inner paths of rotation, each of said inner paths of rotation being in a plane of rotation which is skewed with respect to the plane of rotation of the associated outer path of rotation when said roll is rotating in laterally deflected condition as when under load whereby during each turn the radially inner and outer peripheries of each spacer means move relative to each other with a wobbling motion, each of said spacer means comprising spacer elements each having a slenderness ratio substantially in excess of unity and means for longitudinally clamping and restraining one of the radial ends of each of said spacer members.

Love May 5, 1908 McArn Apr. 27, 1954 

1. A ROLL COMPRISING AN INNER CYLINDRICAL BEAM AND AN OUTER TUBULAR CYLINDRICAL BEAM FORMING A DOUBLE-WALL ROLL WITH A HOLLOW ZONE BETWEEN THE WALLS, ANNULARLY EXTENDING FIRST AND SECOND SPACER MEANS IN SAID HOLLOW ZONE AND IN LOAD-BEARING RELATIONSHIP WITH AND BETWEEN SAID INNER AND OUTER CYLINDRICAL BEAMS, SAID FIRST SPACER MEANS BEING LOCATED INTERMEDIATE THE LONGITUDINAL CENTER OF SAID ROLL AND A FIRST END OF SAID OUTER TUBULAR BEAM, SAID SECOND SPACER MEANS BEING LOCATED INTERMEDIATE THE LONGITUDINAL CENTER OF SAID ROLL AND THE OPPOSITE SECOND END OF SAID OUTER TUBULAR BEAM, EACH OF SAID SPACER MEANS HAVING A RADIALLY OUTER PERIPHERY AND A RADIALLY INNER PERIPHERY, THE RADIALLY OUTER PERIPHERIES OF SAID FIRST AND SECOND SPACER MEANS TRAVELING RESPECTIVELY IN FIRST AND SECOND OUTER PATHS OF ROTATION, THE RADIALLY INNER PERIPHERIES TRAVELING RESPECTIVELY IN FIRST AND SECOND INNER PATHS OF ROTATION, EACH OF SAID INNER PATHS OF ROTATION BEING IN A PLANE OF ROTATION WHICH IS SKEWED WITH RESPECT TO THE PLANE OF ROTATION OF THE ASSOCIATED OUTER PATH OF ROTATION WHEN SAID ROLL IS ROTATING IN LATERALLY DEFLECTED CONDITION AS WHEN UNDER LOAD WHEREBY DURING EACH TURN THE RADIALLY INNER AND OUTER PERIPHERIES OF EACH SPACER MEANS MOVE RELATIVE TO EACH OTHER WITH A WOBBLING MOTION, EACH OF SAID SPACER MEANS COMPRISING SPACER ELEMENTS EACH HAVING A SLENDERNESS RATIO SUBSTANTIALLY IN EXCESS OF UNITY. 